The present invention relates generally to hinge fittings for a reclining vehicle seat structure and, more particularly, to a novel design and arrangement of the lock actuating mechanism for such a seat structure.
Vehicle seats are generally designed for simultaneous forward and rearward adjustment of the seat and seatback members. Other adjustments (e.g., vertical or tilt) of both seat and seatback members, as a unit, may or may not be provided. However, it is often desirable to allow for adjustment of the seatback member, relative to the seat member, to provide an adjustably reclining seatback. Hinge fittings which provide for this type of adjustment normally include a fixed support bracket mounted to the vehicle seat, a seatback support member which is adjustable through a range of reclining positions and which is attached to the seatback and pivotably connected to the fixed support bracket, a locking member to lock the seatback support at various inclined positions, and a lock actuating mechanism for engaging or disengaging the locking member.
An example of hinge fittings of this general type is shown in U.S. Pat. No. 3,999,247 to Cremer. Refinements related to the specific shape and dimensional characteristics of the lock actuating mechanism, which in this patent is a cam, are shown in U.S. Pat. No. 4,223,947, also to Cremer. Another example of this general type of hinge fitting is shown in U.S. Pat. No. 3,973,288 to Pickles.
A problem with hinge fittings of the above-referenced type relates to the location of the lock actuating mechanism and its associated operating handle. When the handle is mounted directly to the pivotable shaft to which the lock actuating mechanism (i.e., the cam in the above-referenced patents) is normally mounted, the handle is relatively inaccessible and is often covered or interfered with by the vehicle seat belts.
Accordingly, it is an object of the present invention to provide a hinge fitting for a reclining vehicle seat structure which has an operating handle located remotely from the lock actuating mechanism.
Another object of this invention is to provide a lock actuating mechanism for a reclining seat hinge fitting which will engage and move the locking member to locking and unlocking positions with relatively little rotational movement of the lock activating mechanism or its associated operating handle.
A further object of this invention is to provide a lock actuating mechanism which, when subjected to a force transmitted by the locking member when the locking member is in the locking position, will tend to urge the locking member toward the locking position.
A still further object of this invention is to provide a hinge fitting which satisfies the above objectives and which is simple and inexpensive to manufacture and install while still providing reliable and smooth operational service.
These and other objectives are achieved in a hinge fitting for a reclining vehicle seat structure which comprises a fixed support bracket, a seatback support member pivoted to the fixed support bracket and adjustable through a range of inclined positions, a locking member pivoted to the support bracket for locking the seatback support member in a desired position, and a lock actuating mechanism for moving the locking member to a locking and an unlocking position. The lock actuating mechanism includes a cam which has a first cam arm to cam the locking member to the locking position and a second cam arm to cam the locking member to the unlocking position. The camming surface on the first cam arm engages the locking member at an engagement point, when the locking member is in the locking position, such that a force applied to the cam by the locking member at the engagement point tends to pivot the cam in a direction which causes the first cam arm to urge the locking member toward the locking position. In a preferred embodiment of the invention, the camming surface on the first cam arm is parabolic in shape. In an especially preferred embodiment of the invention, the lock actuating mechanism includes an operating handle which is mounted near the end of an elongated portion of the support bracket and connected to the cam by a rigid wire rod.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.